Conventionally, in a surgery such as a cataract, a treatment has been performed in which an incision is provided in an ocular tissue such as a cornea (sclera) in the eyeball and a crystalline lens anterior capsule portion, an intracapsular crystalline lens is extracted and removed via the incision, and thereafter, an intraocular lens substituting the crystalline lens is inserted into the eye and disposed in the capsule from the incision.
Especially, in recent years, when inserting the intraocular lens into the eyeball from the incision, in many cases, an insertion tool as illustrated below is used. That is, a leading end opening of an insertion cylindrical portion provided at a leading end portion of a tool main body is inserted into the eyeball through the incision, and the intraocular lens is extruded from the leading end opening of the insertion cylindrical portion by a rod-shaped plunger in a state of being slightly deformed in the tool main body, thereby inserting the intraocular lens into the eyeball. By using such an insertion tool, since it is possible to simply insert the intraocular lens into the eyeball by the use of the incision formed for extraction and removal of the crystalline lens, it is possible to simplify the surgery, and it is possible to suppress an occurrence of astigmatism and an occurrence of infectious disease after surgery.
Incidentally, some above-described intraocular lens insertion tools have a positioning member that holds the position and posture of the intraocular lens in the insertion tools while restricting them, and hold the intraocular lens using the positioning member in the state before use. In this type of intraocular lens insertion tool, the restrictions on the position and posture of the intraocular lens are released by removing the positioning member during use, and the intraocular lens is set to an extrudable state by the plunger (for example, see Patent Literature 1). In this case, depending on a method of removing the positioning member, an inconvenience has occurred in which a lens main body or a support portion of the intraocular lens are interposed by some parts of the positioning member, in some cases, it is not possible to normally release the restrictions on the position and posture of the intraocular lens, and it is difficult to smoothly perform the inserting operation of the intraocular lens.